Metal screen and method of manufacture



' Oct. 5, 1937. A, LANG METAL SCREEN AND METHOD OF MANUFACTURE Filed April 18, 1936 Patented Oct. 5, 1937 METAL SCREEN AND METHOD OF MANU,-'

morons Albert Lang, Berkeley, Calif.

Application April 18, 1936, Serial No. 75,134

11 Claims.

The present invention relates to an improvement in metallic window screens and more particularly to animproved metallic frame for Window screens and a method of manufacturing same. v

An object of the invention is to'provide a metallic screen of novel construction in which the metal thereof is disposed in its most effective position with respect'to the strainsand stresses set up therein by the screen fabric secured thereupon.

Another object of the invention is to provide a strong and inexpensive metal frame for screens of the type having a channel into which the edges of a screen fabric are secured by a metal rod or other member forced into the channel in wedging engagement with the screen fabric.

Another object of the invention is to provide a metal frame fora window screen having a continuous-channel extending around one side thereof in which the inside corners of the channel are rounded to receive the screen fabric and prevent damage thereto atthis point.

Another object of the invention is to provide a metal frame forja screen fabric having a continuouschannel extending therearound in which the, channel is rounded at its corners to'permit.

the use of a screen securing rod having arcuate corner bends- Another object of the invention is to provide a metallic frame for window screens having a.

securing rod channel with a reinforcing reentrant flanged portiondisposed along the inside edge thereof.

A further object of the invention is to provide a method of forming a metallic frame having a channel and a reentrant flanged reinforcing rib along its inside edge which will produce a rounded inner surface in the channel at the-corners of the frame,

For a better understanding of the invention reference should. be had to the accompanying drawing where there is shown by way of illustration and not of limitation, fragmentary parts of a complete window screen constructed in accordance with a preferred embodimerijrof the invention.- 7

In the drawing:

Figure 1 is a fragmentary back view of a window screen having parts broken away to disclose the manner of securing the screenffabric-upon the frame,

Figure 2 is a View similar to Figure i'g showing,

the front surface of a window screen at another corner thereof, a

Figure 3' is ,a back view of a portion of a screen frame member of preferred construction showing the channel and the reinforcing reentrant flange with one'of the mitre cuts made therein to form a-corner in the frame,

Figure 4" is a fragmentary perspective view showing one form of die and shear'which may be used toprovide thecorner forming mitre cut of the frame member illustrated in Figure 3, and

Figures 5, 6, '7 and 8 are fragmentary viewsshowing other formstof frame forming strips which are adaptedto and contemplated by this invention.

In the construction of metallicwindow screens of the character contemplated by this invention,

it is desirable that the completed screen be of,

wedging relation with the screen fabric in thechannel of the frame member. I

The present invention distinguishes over the invention disclosed and claimed in my copending application, Serial Number' 75,133, filed on even date herewith, in that the screen frame has improved and novel features which impart greater stiffnesstothe frame and also provide fa rounded screen fabric supporting surface at the corners of the frame which will prevent damage to'the screen fabric and permit the use of a spring steel rod in the screen receiving channel of the frame. I

At the present time, to provide-suflicient stifiness in a metallic screen frame of the channel type, it is the custom to fold the frame'forming strip to provide a rectangular box-like cross section along the outer edge of the frame and locate the screen receiving channel along the inside edge thereof. The best example of such a construction, at present known. to theapplicant, is illustrated in United states Patent No. 1,187,402, dated June 13, 1916, toClifford Traut. Inthis patent the screen fabric receiving-channel is formed at the inside of a frame portion of rectangular'cross' section by a spaced upstanding flange extending along the inside edge thereof. With such an arrangement it will be readily seen that the unsupported flange thus formed will-be required to take all of the' strain exerted by the screen fabricand consequently a frame of th-is e screen fabric taut under all conditions. As a. re-

sult it is possible, with the construction herein disclosed, to construct larger screens than have been heretofore made. For example, the applicant has made screens of his'improved construction having a length of sixty inches.

.In Figures 1 and}! of the drawing, the screen frame, designated generally by the numeral III, is shown as having a screen fabric II secured thereupon by means of :a. 'wedging rodgi 2. which is adapted to be wedged with the'fledge of the screen fabric in a channel "formed inithe frame I0. 7 In these flguresof thedrawing, the frame I0 is shown as formed of a continuous longitudinally folded strip of metal: I4. having mitre cuts I5 extending from;the inside partially through the folded strip I4 at points corresponding to the corners of the completed fram In Figure 3 of the drawing, there is shown a l I shortdength ofthe'frame forming strip I4 having a cornerformingmltre cut I5; made-therein. As

shown, the mitre cut I5 extends through the inner I edge of the folded strip I4 toa point in line with the surface of the outslde'wall of. the channel I3. 'I'hispermits the uncut portion of thejstrip I4 to be bent around the mitre cut I5 and thus form a right angle cornerforthe screen framelil which will not require any .w'elding or other securing means at this point. :Wh'enthe frame forming strip I4 is provided with four mitre cuts I5 it willv be seen that a complet'eframe It may be formed from a single strip of metal withbut a single joint therein at the meeting ends of the strip IL At the same time-thejframe thus formed will have an;unintem1pted orcontinuous channel I3 ex-' tending entirely therearound. As here illustrated, theframe I II has a flange I 6, extending outwardly from. the channel Iland at the-inner edge of the channel I3 there Isabox-likestructureor rib H of rectangular crosssection which-is formed by a. reentrant flange ll thatis disposed in spaced relation with the outside: wall of the channel I3 soas to provide opposed surfaces between which the screen securing rod I2 may be wedged to secure the screen-fabric- .upon the completed frame. Thisdisposition of a box-like structure orrib I! along theinside of the frame In locates the metal of the frame in itsmost effective position to impart rigidity to the, frame and also provides a relatively; wide surface over which the screen fabric I I cambe drawn and thus greatly reduces the possibilityo'f a fracture of the screen fabric I I when it isbeing' secured upon the frame. In addition ,to disposing the metal ,of .the strip Ilin its most effectivestrainsupporting position upon the frame I0, this construction also lends itself to the formation of a rounded screen fabric engaging surface III-at. the corners of the screen frame. I'his rounded screen fabric engagingsurface I '9-is-produced "by collapsing the box-like .75 atiiucture or rib I'Iladjacentthe mitre cuts I5 so as to curve the reentrant flange I8 inwardly upon the frame ID at these points. In Figure 4 of the drawing, there is shown an a arrangement wherein the mitre cut I5 and the I curvedsurfaces I9 upon the box-like structure II 5 may be formed in a single operation. As here shown, the frame forming strip I4 is disposed in achannel-like shearing die 20 which has a cooperating shearing or punching tool 2|. The

cutting end of the shearing tool 2I is preferably '10 formed 'asan inverted triangular pyramid having two vertically disposed sides which form the sides of the mitre cut I5. With a shearing tool of this character it will be readily seen that as-the point of the shearing tool 2I is forced down upon 15 the frame forming strip I4, as illustrated, it will form a degree mitre cut from the outside wall of the channel I3 inwardly and eventually col lapse the box-like structure II. This will bend,

the reentrant flange I8 outwardly with respect 20 to the channel I3 and thusform' the-curved screen fabric supporting surface I9 previously referred to. In .this .flgure of the drawing, the shearing tool 2| is shown in its initial cutting position, but as having been withdrawn to this" point after making a mitre cut I 5.

In my above identified copendingapplicaticn there is disclosed and claimed the use of a screen retaining rod I2 having outwardly bowed por tions which reinforce the frame III by producing an inherent outward biasing force in the side of T the frame; As therein illustrated and described, the retaining rod I2 has a substantially "square 'bend at each cornervof :theframe I0. A bend 'of' I that character can be formed cold in'ordinary'ai cold drawn' steel or iron rod, but, where spring steel is desired,'it is necessary to heat the rod in order to make a right angle bend'without fracturing the rod at this point. In the present in-" vention this difficulty is overcome by the rounded V surface within thetchannel at each corner of I the frame III, as it is possible with such a rounded,

channel to use a retaining rodhaving a round corner bend such as can'be forrhed'inya spring steel rod without heating the rod. A further ad- 5 vantageobtained by the rounded surface upon theinside of the channel I3 and a rounded'bendin the rod I2 at each corner of the frame,,is that it provides a substantially diagonal dispositionof a portion of the retaining 'rod I2' at this point. v

This imparts additional rigidity at the cornersof the screen frame II) which will serve to retain,

the frame II) in its original squared condition. While the screen frame I0 is shown and de-- scribed above ashaving a box-like structure I1 formed by bending the metal of the frame forming strip I 4 uponitself to provide a reehtrant' flange I8, it is to be understood that thisbox-like reinforcing structure I1 upon the screen frame may take a number of different forms. f I

In Figure 5 there is shown'a' portion of a frame forming strip, designated by the numeral 22, having a box-like structure 23of rectangular outlinein which areentrant flange 24 terminates at the bottom of the channel I3 in'an additional flange 25. 1 v v a I In Figure 6 of the drawing, there is shown a frame forming strip 26 having a box-like structure 2I of rectangular. cross section in which a reentrant flanged portion 28 terminates in an70' outwardly extending flange 29 which engages the bottom surface of the channel I3. I v In Figure 7 of the drawing, the box-like reinforcing structure along the inside edge of the frame forming strip, designated by the numeral ,75

30, is a cylindrical beading 3| extending along the inside edge thereof. This beading 3| is formed by rolling the metal at this point inwardly into the channel 13 so that the free edge thereof may be collapsed to provide the curved surface at the corners of the frame when the mitre cuts M are formed therein, as described above. t

In Figure 8 of the drawing, there is shown a portion of a frame forming strip 3| having the channel l3 completed by rolling up the inner edge of the strip 3|. This construction provides a rounded bearing surface 33 over which the screen fabric may be drawn and the free edge thereof may be collapsed to provide the rounded corner, as above described, when themitre cuts are formed therein, as contemplated by this invention.

In all of the arrangements disclosed above, it will be noted that the frame forming strips have the stiffening flanges or ribs disposed along the inside of thechannel l3, and as a result the stresses exerted bythe screen fabric l I will be applied directly upon the major part of the frame rather than upon an inwardly disposed and unsupported flange, as is disclosed by the prior art. i

While I have, for the sake of clearness and in order to disclose the invention so that the same can be readily understood, described and illustrated specific devices and arrangements, I desire to have it understood that this invention is not limited to the specific means disclosed, but may be embodied in other ways that will suggest themselves to persons skilled in the art. It is believed that this invention is new and it is desired to claim it so that all such changes as come within the scope of the appended claims are to be considered as part of this invention.

Having thus described my invention, what I claim and desire to secure by Letters Patent is- 1. A metallic frame for a window screen having its sides formed of a continuous strip of sheet metal turned inwardly along its inside edge to provide a support in the plane of the screen substantially wider than the thickness of said metal strip over which the screen fabric may be drawn, and having an upwardly turned portion with an outwardly extending flange forming in conjunction with said support a channel outside of said support into which a screen securing rod may be disposed, the outwardly extending flange upon said upwardly turned portion serving to rein-. force said latter portion and as a means for securing the frame upon a supporting surface.

2. A metallic frame for a window screen having its sides formed of a continuous strip of sheet metal folded inwardly upon itself along its inner edge to form a hollow rectangular rib over which the screen fabric may be drawmand having an upwardly turned portion with an outwardly extending flange along its outer edge which in conjunction with said rectangular rib forms a support engaging surface and a channel outside of said rib into which the edge of the screen fabric and a securing rod may be disposed in a concealed manner.

3. A metallic frame for a window screen having its sides formed of a continuous strip of sheet metal turned inwardly upon itself along its inner edge to provide a hollow reinforcing rib over which the screen fabric may be drawn, and having an upwardly turned portion with an outwardly extending reinforcing and support engaging flange disposed, in spaced relation to said reinforcing rib and forming in conjunction therewith a channel into which the edge of a screen fabric and a securing rod may be disposed.

4. In a window screen frame, the combination of a strip of sheet metal folded lengthwise to form a channel having a reentrant flange disposed intermediate the sides thereof and forming a box? like structure along the inside ,ofthe strip over which a screen fabric is drawn, said strip being bent at mitre cuts extending through said boxlike structure and the bottom of the channel at points corresponding to the corners of the frame,

a screen fabric having its edges disposed over ,said box-like structure, and a reinforcing rod disposed in said channel in wedging relation bewhich a screen fabric is drawn, said strip having mitre cuts extending through said box like structure and the bottom only of the channel theremaining portion of the channel being bent around said mitre cuts to form the corners of the frame, a screen fabric having its edges disposed over said box-like structure, a reinforcing rod disposed in said channel in wedging relation between the outside wall thereof and the reentrant flange of the box-like structure, and an outwardly extending flange along the outside of said channel for attaching the screen to a surface, whereby said reinforcing rod will be concealed.

6. In a window screen frame, the combination of a strip of sheet metal folded lengthwise to form a main channel having .a second oppositely disposed channel intermediate the sides of said main channel forming a bearing surface over which a screen fabric is drawn, said strip having mitre cuts extending through said oppositely disposed channel and a portion of the main channel and being bent around said mitre cuts to form the corners of the frame, a screen fabric having its edges said main channel opposite the bearing surface formed by said intermediate channel providing a support engaging surface upon said frame.

'7. The method of forming a metallic frame for window screens of the type having a continuous screen fabric securing channel extending therearound, which comprises folding a strip of sheet metal to form a channel with a reentrant collapsible overhanging portion, shearing .a mitre cut into the bottom of said channel and saidreentrant collapsible overhanging portion, collapsing said reentrant overhanging portion at each side of said mitre cut, and finally bending the uncut portion of said strip at a right angle about said mitre cut, whereby a rounded surface will be provided at the corners of said channel when said frame is formed. I

8. The method of forming'a metallic frame for window screens of the type having a continuous screen fabric securing channel extending therearound, which comprises foldinga trip of sheet metal to form a wide channel wi a reentrant collapsible portion along the inside edge of said wide channel, shearing a. mitre out into the bot- 7 at each side of said mitre cut; and finally bending the uncut portion of said strip at a right angle about said mitre cut, 'whereby a roundedsurface will be provided at the-corners of said channel when said frame is formed.

' 9. Thelmethodzof forming a metallic framefor window screens of the type having a continuous channel extending therearound for the reception of a'screen fabric and securing means, which comprises folding a strip of sheet metal longitudinally to form a wide channel, and by a further bending forming a reentrant collapsible inwardly disposed portion within said channel over which the screen fabric is to be drawn, shearing a mitreecut into a portionv of said channel and entirely through said reentrant'collapsible portion in a manner that will collapse s'aid'reentrant collapsible portion at each side, of the mitre cu't, and finally bending the uncut: portion of said strip at a right angle about said mitrecut'substantially as described.

.10. A metallic frame for a window screen com- 25 prising a continuous strip of sheet metal bent lengthwise to form a channel. having an outwardly extending flange along its outside edge and inwardly and downwardly extending flanges along the inside edge of said channel forming 'a rectangular box-like rib, said strip being provided with mitre cuts extending through said rectangular box-like rib and including the bottom of said channel and being bent at the uncut portion thereof to close the mitre cuts and form the corners of the frame, whereby said frame will have a continuous rectangular reinforcing box-like rib along its inside edge over which-a screen forming fabric may be drawn and a continuous outwardly extending support engaging flange along its outside edge.- I a 11. In a metallic window screen the combination of a strip of sheet metal folded to form a channel-like recess for a screen fabric securing rod having ahollow rectangular rib along the inner edge thereof over which the edges of a screen fabric are drawn, said strip being provided with mitre cuts at the corners of the'frame and said rectangular rib being collapsed at each side of these mitre cuts, whereby a round'ed screen engaging surface will be providedin the channel-like recess at the corners of the frame, a'screen fabric 1 for saidframehaving its edges extendingover said rectangular rib, and a securing rod having a rounded right angle bend disposed in said channel-like recess and extending a'roundthecorners of the frame in clamping engagement with said screen fabric. I

= a ALBERT LANG 

